Agricultural combine harvesters are large machines which harvest, thresh, separate and clean agriculturally cultivated grain-bearing crops. The clean grain obtained is stored in a grain tank arranged on the combine harvester. The straw removed by threshing is generally either chopped and distributed on the field across the width of the cutting section or is guided around the straw chopper and deposited on the field unchopped in a swath so that it can be picked up later by a baler. The crop residues remaining at the rearward outlet of the cleaning device, such as chaff and small pieces of straw, are distributed on the field by a chaff spreader or passed through the straw chopper and distributed on the field. The last-mentioned solution has the advantage that there is no need for a separate chaff spreader but makes it necessary to guide the straw past the rear of the straw chopper in the swath operating mode.
An example of a combine harvester of this type is described in DE 10 2005 040 125 A1 which is considered to establish the generic type. The straw output by the axial threshing and separating device is thrown to the rear by a drum conveyor. In the chopping mode, the straw impacts against a pivotable flap which conducts the straw downward into the straw chopper. The flap can be pivoted upward for the swath deposit operation in which the straw passes onto a straw chute which is arranged above the straw chopper and on which the straw slides downward and rearward and is output onto the field above the straw chopper. A straw conveyor which operates in an undershot or overshot manner and can be embodied as a drum conveyor or conveyor belt is arranged above the straw chute.
The straw deposited in the swath is intended to lie as loosely as possible so that it can possibly still dry off somewhat and can easily be collected with a material pick-up. Although the drum or belt conveyor which is known in the prior art according to DE 10 2005 040 125 A1 is capable of conveying the straw, it can scarcely loosen the straw up.
The object of the invention is providing a combine harvester of the type stated above in which the abovementioned problems occur to a reduced extent, if at all.